From 1f271a981545d0e4adff646bc2f8af69853fbaf2 Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Tue, 4 Feb 2020 21:47:15 +0200
Subject: [PATCH] lib/logger: add `-loggerOutput` command-line flag
This flag allows changing log output from `stderr` to `stdout` if `-loggerOutput=stdout` is set.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/306
---
lib/logger/logger.go | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/lib/logger/logger.go b/lib/logger/logger.go
index 403228016b..b2a29a7202 100644
--- a/lib/logger/logger.go
+++ b/lib/logger/logger.go
@@ -4,6 +4,7 @@ import (
"errors"
"flag"
"fmt"
+ "io"
"log"
"os"
"runtime"
@@ -19,6 +20,7 @@ import (
var (
loggerLevel = flag.String("loggerLevel", "INFO", "Minimum level of errors to log. Possible values: INFO, ERROR, FATAL, PANIC")
loggerFormat = flag.String("loggerFormat", "default", "Format for logs. Possible values: default, json")
+ loggerOutput = flag.String("loggerOutput", "stderr", "Output for the logs. Supported values: stderr, stdout")
)
// Init initializes the logger.
@@ -27,12 +29,26 @@ var (
//
// There is no need in calling Init from tests.
func Init() {
+ setLoggerOutput()
validateLoggerLevel()
validateLoggerFormat()
go errorsLoggedCleaner()
logAllFlags()
}
+func setLoggerOutput() {
+ switch *loggerOutput {
+ case "stderr":
+ output = os.Stderr
+ case "stdout":
+ output = os.Stdout
+ default:
+ panic(fmt.Errorf("FATAL: unsupported `loggerOutput` value: %q; supported values are: stderr, stdout", *loggerOutput))
+ }
+}
+
+var output io.Writer
+
func validateLoggerLevel() {
switch *loggerLevel {
case "INFO", "ERROR", "FATAL", "PANIC":
@@ -145,7 +161,7 @@ func logMessage(level, msg string, skipframes int) {
// Serialize writes to log.
mu.Lock()
- fmt.Fprint(os.Stderr, logMsg)
+ fmt.Fprint(output, logMsg)
mu.Unlock()
// Increment vm_log_messages_total